I have two questions about customizing Squarespace forms, and I'm not sure either is possible:
We often send existing contacts to the form and would like to auto-populate form values based on their information. Ideally, we'd send the contact a link to the correct page with a parameter for their email address – website.com/form-page?em=chris@example.com – and some javascript would parse the parameters and pre-populate the Email field on the form
We'd also like to include some metadata about the form, like the version number of the form they're submitting since they frequently change. Ideally, we'd put a Version Number field on the form with a default value (e.g., "v1.0") and mark it as hidden, but that doesn't seem to be possible with Squarespace forms